1. Field of the Invention
Wheels for motor vehicles, such as, for example, automobiles and motor cycles, and wheels for motorassisted bicycles, bicycles, trailers and hand carts have a rim in which a tire of natural or synthetic rubber is inserted. Depending on the type of tire, either pneumatic tires or solid rubber tires are used here.
Depending on the type of vehicle and load limit, one or other type of tire is preferred, a solid rubber tire having the advantage over the use of pneumatic tires that it requires virtually no maintenance and is insensitive to minor damage to the tire skin. On the other hand, pneumatic tires have the advantage that they are suitable for higher speeds and have better shock absorption.
2. Description of the Prior Art
Known pneumatic tires have a substructure, also referred to as the carcass, consisting of a certain number of crossed layers of reinforcing fibers, such as, for example, silk, polyamide or metal. The carcass may have a multi-layer form, at least one layer consisting of a dense weave of reinforcing fibers for protection from external damage.
The wheels intended for equipping with pneumatic tires may alternatively be formed with or without an inner tube. Wheels without a separate inner tube require that the space between the rim and the pneumatic tire be sealed air-tight, as, for example, in the case of automobiles.
In the case of bicycles, which preferably have wheels with an inner tube, the total energy which is required for movement is supplied by the rider's muscles. In this case, tire designers therefore pay particular attention to low tire weight and to minimum resistance to rolling. The result of this is that in particular tires for bicycles can be very easily damaged owing to a lack of strength and that even slight damage to the tire skin leads to damage to the inner tube and hence to immediate and complete loss of air, which finally prevents further riding.